fix bugs generated by _steps null in discoverFeatures and _alreadyCompletedSteps methods

example/.flutter-plugins-dependencies

@@ -1 +1 @@
-{"info":"This is a generated file; do not edit or check into version control.","plugins":{"ios":[{"name":"shared_preferences","path":"/Users/ganeshr/.pub-cache/hosted/pub.dartlang.org/shared_preferences-0.5.12/","dependencies":[]}],"android":[{"name":"shared_preferences","path":"/Users/ganeshr/.pub-cache/hosted/pub.dartlang.org/shared_preferences-0.5.12/","dependencies":[]}],"macos":[{"name":"shared_preferences_macos","path":"/Users/ganeshr/.pub-cache/hosted/pub.dartlang.org/shared_preferences_macos-0.0.1+10/","dependencies":[]}],"linux":[{"name":"path_provider_linux","path":"/Users/ganeshr/.pub-cache/hosted/pub.dartlang.org/path_provider_linux-0.0.1+2/","dependencies":[]},{"name":"shared_preferences_linux","path":"/Users/ganeshr/.pub-cache/hosted/pub.dartlang.org/shared_preferences_linux-0.0.2+2/","dependencies":["path_provider_linux"]}],"windows":[{"name":"path_provider_windows","path":"/Users/ganeshr/.pub-cache/hosted/pub.dartlang.org/path_provider_windows-0.0.4+1/","dependencies":[]},{"name":"shared_preferences_windows","path":"/Users/ganeshr/.pub-cache/hosted/pub.dartlang.org/shared_preferences_windows-0.0.1+1/","dependencies":["path_provider_windows"]}],"web":[{"name":"shared_preferences_web","path":"/Users/ganeshr/.pub-cache/hosted/pub.dartlang.org/shared_preferences_web-0.1.2+7/","dependencies":[]}]},"dependencyGraph":[{"name":"path_provider_linux","dependencies":[]},{"name":"path_provider_windows","dependencies":[]},{"name":"shared_preferences","dependencies":["shared_preferences_linux","shared_preferences_macos","shared_preferences_web","shared_preferences_windows"]},{"name":"shared_preferences_linux","dependencies":["path_provider_linux"]},{"name":"shared_preferences_macos","dependencies":[]},{"name":"shared_preferences_web","dependencies":[]},{"name":"shared_preferences_windows","dependencies":["path_provider_windows"]}],"date_created":"2020-10-07 20:05:17.296552","version":"1.22.0"}
+{"info":"This is a generated file; do not edit or check into version control.","plugins":{"ios":[{"name":"shared_preferences","path":"/Users/ganeshr/.pub-cache/hosted/pub.dartlang.org/shared_preferences-0.5.12/","dependencies":[]}],"android":[{"name":"shared_preferences","path":"/Users/ganeshr/.pub-cache/hosted/pub.dartlang.org/shared_preferences-0.5.12/","dependencies":[]}],"macos":[{"name":"shared_preferences_macos","path":"/Users/ganeshr/.pub-cache/hosted/pub.dartlang.org/shared_preferences_macos-0.0.1+10/","dependencies":[]}],"linux":[{"name":"path_provider_linux","path":"/Users/ganeshr/.pub-cache/hosted/pub.dartlang.org/path_provider_linux-0.0.1+2/","dependencies":[]},{"name":"shared_preferences_linux","path":"/Users/ganeshr/.pub-cache/hosted/pub.dartlang.org/shared_preferences_linux-0.0.2+2/","dependencies":["path_provider_linux"]}],"windows":[{"name":"path_provider_windows","path":"/Users/ganeshr/.pub-cache/hosted/pub.dartlang.org/path_provider_windows-0.0.4+1/","dependencies":[]},{"name":"shared_preferences_windows","path":"/Users/ganeshr/.pub-cache/hosted/pub.dartlang.org/shared_preferences_windows-0.0.1+1/","dependencies":["path_provider_windows"]}],"web":[{"name":"shared_preferences_web","path":"/Users/ganeshr/.pub-cache/hosted/pub.dartlang.org/shared_preferences_web-0.1.2+7/","dependencies":[]}]},"dependencyGraph":[{"name":"path_provider_linux","dependencies":[]},{"name":"path_provider_windows","dependencies":[]},{"name":"shared_preferences","dependencies":["shared_preferences_linux","shared_preferences_macos","shared_preferences_web","shared_preferences_windows"]},{"name":"shared_preferences_linux","dependencies":["path_provider_linux"]},{"name":"shared_preferences_macos","dependencies":[]},{"name":"shared_preferences_web","dependencies":[]},{"name":"shared_preferences_windows","dependencies":["path_provider_windows"]}],"date_created":"2020-10-07 20:05:17.296552","version":"1.22.0"}

example/.gitignore

@@ -22,6 +22,7 @@
 **/doc/api/
 .dart_tool/
 .flutter-plugins
+.flutter-plugins-dependencies
 .packages
 .metadata
 .pub-cache/

lib/src/foundation/bloc.dart

@@ -110,7 +110,7 @@ class Bloc {
 
     _steps = steps;
     _stepsToIgnore = await _alreadyCompletedSteps;
-    _steps = _steps.where((s) => !_stepsToIgnore.contains(s)).toList();
+    _steps = _steps?.where((s) => !_stepsToIgnore.contains(s))?.toList() ?? [];
     _activeStepIndex = -1;
 
     await _nextStep();
@@ -156,9 +156,7 @@ class Bloc {
   Future<Set<String>> get _alreadyCompletedSteps async {
     if (!recordInSharedPrefs) return {};
     final prefs = await SharedPreferences.getInstance();
-    return _steps
-        .where((s) => prefs.getBool('$sharedPrefsPrefix$s') == true)
-        .toSet();
+    return _steps?.where((s) => prefs.getBool('$sharedPrefsPrefix$s') == true)?.toSet() ?? {};
   }
 
   /// Returns true iff this step has been previously

pubspec.yaml

@@ -3,7 +3,7 @@ description: >-
   A Flutter package that implements Material Design Feature discovery
   to show a description of specific features to new users.
   See https://tinyurl.com/FeatureDiscovery
-version: 0.12.0+2
+version: 0.12.1+3
 homepage: https://github.com/ayalma/feature_discovery
 
 environment: